Answer:
Pietraforte stone was selected, because it was strong, had a color that would turn light brown over time, and it developed interesting textures for the rough center.
Step-by-step explanation:
According to a different source, these are the options that come with this question:
- Pietra Bigia was used to make the streets and squares of early Renaissance Florence. This stone is cemented by the mineral calcite and this characteristic made it possible to cut planes on the sites and yet leave the center rough.
- Pietra Serena stone was selected. Pietra Serena means “calm stone” in Italian. The texture is pretty uniform with a bluish to grayish color at first. It could be quarried in a way as to make large blocks suitable for rustication.
- Pietraforte stone was selected, because it was strong, had a color that would turn light brown over time, and it developed interesting textures for the rough center.
- As the city of Florence continued to expand to the periphery, people cut flat spaces by quarrying the rock formations of Pratomagno. Thus, Pratomagno stone was used for the rusticated facades.
Rustication is a technique used in masonry. This was popular in the ancient world, but became widely used during the Italian Renaissance. This technique consists of cutting the edges of the stone flat, while leaving the center rough and facing outward.
During the fifteenth century, this technique became popular in Florence. The use of it in private houses established a model for elegant urban residences throughout Europe. These constructions usually used a stone known as "pietra forte." Pietra forte is a strong type of stone that turns brown over time and presents interesting textures for the rough center. It was also widely available in the quarries that surrounded Florence.